Fulgurite is a hollow, tubular glassy mass produced by the energy released by lightning on quartz-rich sandy soil. The heat generated by the electrical discharge melts the quartz-containing silica sand, giving rise to fulgurite. Long pieces of fulgurite are rare. The generally grayish color typical of fulgurite is due to the numerous impurities present in the sand that remain embedded within the glass. A fulgurite is also called petrified lightning, as it appears like a lightning imprint on the ground. It is a fragile piece. Fulgorite: Sahara Desert Mauritania 74 x 21 x 12 mm about 6 grams the piece for sale is what you see in photos! please be careful with the description and measures Standard shipping ( 2-7 days for Italy ) ( 10-20 days for Europe ) ( 15-40 days for rest of the world ) if you want fast shipping, please contact me immediately after the auction win